SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '719155d20061c0ca0fbf84f93188541af013049a30e4f7b4bb6fbbf6f685b0db' 
  AND token = 'TOylPmlpMderLigHX3fAHmpZSVYSnNA3yw1kRjg3000=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}